1. Field of the Invention
The present invention relates to agricultural tillage implements, and, more particularly, to agricultural field cultivators.
2. Description of the Related Art
Farmers utilize a wide variety of tillage implements to prepare soil for planting. Some such implements include two or more sections coupled together to perform multiple functions as they are pulled through fields by a tractor. For example, a field cultivator is capable of simultaneously tilling soil and leveling the tilled soil in preparation for planting. A field cultivator has a frame that carries a number of cultivator shanks with shovels at their lower ends for tilling the soil. The field cultivator converts compacted soil into a level seedbed with a consistent depth for providing excellent conditions for planting of a crop. Grass or residual crop material disposed on top of the soil is also worked into the seedbed so that it does not interfere with a seeding implement subsequently passing through the seedbed.
A field cultivator as described above may also include an optional rear auxiliary implement for finishing the seedbed for seeding. For example, a rear auxiliary implement may include a spike tooth harrow, spring tooth harrow, rolling (aka. crumbler) basket, cultivator shanks etc., or any combination thereof.
As tillage implements become wider and wider over time, it becomes more difficult to keep the transport size of the implement within manageable limits. It also becomes more difficult to convert the tillage implement from an operating mode to a transport mode, or vice versa, without requiring too much time and difficulty on the part of the operator. It is desirable for the tillage implement to be converted from one mode to the other while the operator remains within the operator cab, through the use of hydraulics or other actuators.
With wide field cultivators as described above, it is known to have a main frame section and one or more wing sections which are foldable relative to each other such that the wing sections can be folded to a compact transport mode. Such wide field cultivators typically fold the wing sections up and over the main frame section (known as a top fold). As the size of field cultivators increase, it is important for the cultivator to track properly behind the traction unit both when in the field mode and the transport mode. Tracking of the cultivator refers to the transverse angle of the frame sections relative to the longitudinal direction of the pull hitch, or travel direction of the cultivator. If the tillage implements (e.g., cultivator shovels) are in a working position in the ground, any angular offset of the cultivator caused by improper tracking can be further exacerbated by the difference in force angles/vectors exerted on the tillage implements by the ground.
What is needed in the art is a tillage implement which properly tracks behind the traction unit.